The Sixth Sense and The Others have the best. There are a few movies that would not be that great of movies without the revelation toward the ending, such as Orphan, whereby the very "twist" clears up just about all suspension of disbelief found in all events leading up to it.

Although I've got to admit: Split (2016) will probably have my vote. I love everything about that ending. I mean, I love everything about Psycho (1960) and A Nightmare on Elm Street (1984), but in terms of sheer greatness of ending Split is rather unique. It's just... It was practically never done before in that respect. It's unique.